Allow mods to specify shader import namespace (MinecraftForge#9021)

patches/minecraft/net/minecraft/client/renderer/ShaderInstance.java.patch

@@ -30,3 +30,28 @@
           InputStream inputstream = resource.m_215507_();
 
           try {
+@@ -232,11 +_,11 @@
+                private final Set<String> f_173369_ = Sets.newHashSet();
+
+                public String m_142138_(boolean p_173374_, String p_173375_) {
+-                  p_173375_ = FileUtil.m_179924_((p_173374_ ? s1 : "shaders/include/") + p_173375_);
+-                  if (!this.f_173369_.add(p_173375_)) {
++                  // FORGE: use the mod's namespace to look up resources if specified
++                  ResourceLocation resourcelocation = net.minecraftforge.client.ForgeHooksClient.getShaderImportLocation(s1, p_173374_, p_173375_);
++                  if (!this.f_173369_.add(resourcelocation.toString())) {
+                      return null;
+                   } else {
+-                     ResourceLocation resourcelocation = new ResourceLocation(p_173375_);
+
+                      try {
+                         Reader reader = p_173341_.m_215597_(resourcelocation);
+@@ -262,7 +_,8 @@
+
+                         return s2;
+                      } catch (IOException ioexception) {
+-                        ShaderInstance.f_173323_.error("Could not open GLSL import {}: {}", p_173375_, ioexception.getMessage());
++                        // FORGE: specify the namespace of the failed import in case of duplicates from multiple mods
++                        ShaderInstance.f_173323_.error("Could not open GLSL import {}: {}", resourcelocation, ioexception.getMessage());
+                         return "#error " + ioexception.getMessage();
+                      }
+                   }

src/main/java/net/minecraftforge/client/ForgeHooksClient.java

@@ -17,6 +17,7 @@
 import com.mojang.math.Matrix4f;
 import com.mojang.math.Vector3f;
 import net.minecraft.ChatFormatting;
+import net.minecraft.FileUtil;
 import net.minecraft.client.Camera;
 import net.minecraft.client.KeyMapping;
 import net.minecraft.client.Minecraft;
@@ -1155,4 +1156,12 @@ public static int getMaxMipmapLevel(int width, int height)
                 Mth.log2(Math.max(1, height))
         );
     }
+
+    public static ResourceLocation getShaderImportLocation(String basePath, boolean isRelative, String importPath)
+    {
+        final var loc = new ResourceLocation(importPath);
+        final var normalised = FileUtil.normalizeResourcePath(
+            (isRelative ? basePath : "shaders/include/") + loc.getPath());
+        return new ResourceLocation(loc.getNamespace(), normalised);
+    }
 }

src/test/java/net/minecraftforge/debug/client/rendering/ShaderResourcesTest.java

@@ -0,0 +1,77 @@
+/*
+ * Copyright (c) Forge Development LLC and contributors
+ * SPDX-License-Identifier: LGPL-2.1-only
+ */
+
+package net.minecraftforge.debug.client.rendering;
+
+import java.io.IOException;
+
+import org.slf4j.Logger;
+
+import com.mojang.blaze3d.vertex.DefaultVertexFormat;
+import com.mojang.logging.LogUtils;
+
+import net.minecraft.client.renderer.ShaderInstance;
+import net.minecraft.resources.ResourceLocation;
+import net.minecraftforge.api.distmarker.Dist;
+import net.minecraftforge.client.event.RegisterShadersEvent;
+import net.minecraftforge.eventbus.api.SubscribeEvent;
+import net.minecraftforge.fml.DistExecutor;
+import net.minecraftforge.fml.common.Mod;
+import net.minecraftforge.fml.javafmlmod.FMLJavaModLoadingContext;
+import net.minecraftforge.fml.loading.FMLEnvironment;
+
+@Mod(ShaderResourcesTest.MODID)
+public class ShaderResourcesTest
+{
+    private static Logger LOGGER;
+
+    public static final String MODID = "shader_resources_test";
+    private static final boolean ENABLE = false;
+
+    public ShaderResourcesTest()
+    {
+        if (ENABLE)
+        {
+            LOGGER = LogUtils.getLogger();
+
+            DistExecutor.unsafeRunWhenOn(Dist.CLIENT,() -> ClientInit::new);
+        }
+    }
+
+    private class ClientInit
+    {
+        public ClientInit()
+        {
+            final var modEventBus = FMLJavaModLoadingContext.get().getModEventBus();
+
+            modEventBus.addListener(ClientInit::registerShaders);
+        }
+
+        public static void registerShaders(final RegisterShadersEvent event)
+        {
+            if (!ENABLE)
+                return;
+
+            try
+            {
+                event.registerShader(
+                        new ShaderInstance(
+                                event.getResourceManager(),
+                                new ResourceLocation(MODID, "vertex_cubemap"),
+                                DefaultVertexFormat.POSITION),
+                        shader ->
+                        {
+                            LOGGER.info("Completely loaded shader {} with no issues", shader.getName());
+                        });
+
+                LOGGER.info("Loaded registered shaders with no exceptions");
+            }
+            catch (IOException e)
+            {
+                LOGGER.error("Failed to load shaders with exception", e);
+            }
+        }
+    }
+}

src/test/resources/META-INF/mods.toml

@@ -17,6 +17,8 @@ license="LGPL v2.1"
 
 [[mods]]
     modId="advancement_event_test"
+[[mods]]
+    modId="shader_resources_test"
 
 # LEGACY TEST CASES
 ###### The mods below are from the old test framework and need to be yeeted later again.

src/test/resources/assets/shader_resources_test/shaders/core/vertex_cubemap.fsh

@@ -0,0 +1,8 @@
+#version 150
+
+#moj_import <fog.glsl>
+#moj_import <shader_resources_test:cubemap_includes.glsl>
+
+void main() {
+    fragColor = vec4(vertexPos, 0);
+}

src/test/resources/assets/shader_resources_test/shaders/core/vertex_cubemap.json

@@ -0,0 +1,17 @@
+{
+    "blend": {
+        "func": "add",
+        "srcrgb": "srcalpha",
+        "dstrgb": "1-srcalpha"
+    },
+    "vertex": "shader_resources_test:vertex_cubemap",
+    "fragment": "shader_resources_test:vertex_cubemap",
+    "attributes": [
+    ],
+    "samplers": [
+    ],
+    "uniforms": [
+        { "name": "ModelViewMat", "type": "matrix4x4", "count": 16, "values": [ 1.0, 0.0, 0.0, 0.0, 0.0, 1.0, 0.0, 0.0, 0.0, 0.0, 1.0, 0.0, 0.0, 0.0, 0.0, 1.0 ] },
+        { "name": "ProjMat", "type": "matrix4x4", "count": 16, "values": [ 1.0, 0.0, 0.0, 0.0, 0.0, 1.0, 0.0, 0.0, 0.0, 0.0, 1.0, 0.0, 0.0, 0.0, 0.0, 1.0 ] }
+    ]
+}

src/test/resources/assets/shader_resources_test/shaders/core/vertex_cubemap.vsh

@@ -0,0 +1,13 @@
+#version 150
+
+in vec3 Position;
+
+uniform mat4 ProjMat;
+uniform mat4 ModelViewMat;
+
+out vec3 vertexPos;
+
+void main() {
+    gl_Position = ProjMat * ModelViewMat * vec4(Position, 1.0);
+    vertexPos = Position;
+}

src/test/resources/assets/shader_resources_test/shaders/include/cubemap_includes.glsl

@@ -0,0 +1,5 @@
+#version 150
+
+in vec3 vertexPos;
+
+out vec4 fragColor;